I want to get a sense from people as to how important it is to actually check off every item on the socialization lists (keeping in mind some of these are like 100+ long)?

We've had Hans for 3 weeks, got him at 8 weeks old. He's just a little gem of a character. He's really blossoming, growing like a weed, loves his new pack and is basically tireless. If he's not sleeping he's basically operating at mach speed. He is really brilliant and we used clicker training to teach him to sit, down, shake a paw, jump and look at us and now he's learning "take it".

He gets his second set of shots tomorrow, so we haven't taken him on walks around the neighbourhood as practically every house has a dog and a couple of the sketchier neighbours let theirs loose even though they're not trained well at all so I didn't want to risk it. But the vet says he can start going on walks and to the park about 4-5 days after his shots tomorrow. He starts puppy kindergarten in 10 days.

Rather than checking off items on the list, we've tried to adapt him to our lifestyle and expose him to things which he'll see regularly, as well as some things that he won't see regularly. This is what we've done so far:
- taken him shopping (not to pet stores), sometimes he's allowed in the store, other times one of us stays in front with him and greets other shoppers while the other person shops...at first he wasn't sure about shopping carts and the noise they make but now he's an old pro
- driven him around in the car in his crate a lot
- taken him to my parents' and my in-laws' houses quite a few times since they both have stable older dogs for him to play with and since he will stay with them when we travel
- taken him to neighbours' houses
- had puppy dates with my sister-in-law's Bichon puppy once a week, at her place or ours
- had about 30 different people visit Hans at our place, from the very young to the very old, different sizes, races, etc.
- introduced him to the neighbourhood kids - there is a school bus stop on our corner so I've taken him there in the morning so the kids can pet him and say hi
- taken him to the neighbour's house, they've got 4 boys ages 8-15 and they put him on his leash and then "walked" him around their yard and played hockey with him (they'd hit the ball, he'd run after it)
- introduced him to a couple of babies, a newborn and a 2-month old so he could get used to their scent and the sound of them fussing and crying and get used to their strollers
- introduced him to his dog walker at 10 weeks and then she started coming over at 11 weeks every day to let him into the yard and play with him

Obviously when he starts going on walks it will be easier to meet even more people, for example people with canes or in wheelchairs, etc. But are we doing ok so far or do we really need to use a list?